Explanation:
In July of 1994 pieces of Comet
Shoemaker-Levy 9
collided with planet Jupiter.
The explosive impacts sent plumes of debris high into the Jovian
atmosphere creating
dark markings or scars, visible for a time
against the cloud bands.
Remarkably, 15 years later,
another impact scar was
discovered in the Jovian atmosphere by amateur astronomer Anthony
Wesley as he examined images of the gas giant taken
from his home observatory just outside Murrumbateman NSW Australia.
Jupiter's south pole is at the top in this July 19 discovery image,
with Jupiter rotating from right to left.
The dark marking, also likely caused by a comet or asteroid impact,
is near the top of the view, left of a pre-existing, whitish, oval-shaped
storm.
NASA's Infrared Telescope Facility images from Mauna
Kea, Hawaii later confirmed the likely
impact site's dark scar and plume of particles in Jupiter's upper
atmosphere.
Since 2006, major discovery observations by amateur astronomers
have also included two red spots on Jupiter.